# Interface engineering of graphene nanosheet reinforced ZrB$_2$ composites by tuning surface contacts

## TL;DR

This study uses density functional theory to analyze and compare the structure and mechanical behavior of heterophase interfaces in graphene-reinforced ZrB$_2$ composites, highlighting how surface chemistry influences interface properties.

## Contribution

It systematically investigates the atomic-scale interface structures and interactions, revealing how surface chemistry and contact types affect mechanical response and bonding in graphene/ZrB$_2$ composites.

## Key findings

- Zr-C-Zr interfaces exhibit strong chemical bonding.
- B-C-B interfaces show weak π-π stacking interactions.
- Surface chemistry controls interface structure and mechanical response.

## Abstract

The mechanical properties of heterophase interfaces are critically important for the behaviour of graphene-reinforced composites. In this work, the structure, adhesion, cleavage and sliding of heterophase interfaces, formed between a ZrB$_2$ matrix and graphene nanosheets, are systematically investigated by density functional theory, and compared to available experimental data. We demonstrate that the surface chemistry of the ZrB$_2$ matrix material largely shapes the interface structures (of either Zr-C-Zr or B-C-B type) and the nature of the interfacial interaction. The Zr-C-Zr interfaces present strong chemical bonding and their response to mechanical stress is significantly influenced by graphene corrugation. In contrast B-C-B interfaces, interacting through the relatively weak $\pi$-$\pi$ stacking, show attributes similar to 2D materials heterostructures. Our theoretical results provide insights into the interface bonding mechanisms in graphene/ceramic composites, and emphasize the prospect for their design via interface engineering enabled by surface contacts.